%0 Journal Article %T The use of relative speed zones in Australian football: are we really measuring what we think we are? %J International journal of sports physiology and performance %D 2018 %A Murray, Nick B. %A Gabbett, Tim J. %A Townshend, Andrew D. %V 13 %N 4 %P 442-451 %X OBJECTIVES: This study aimed to examine the difference between absolute and relative workloads, injury likelihood, and the acute:chronic workload ratio (ACWR) in elite Australian football.

DESIGN: Single cohort, observational study.

METHODS: Forty-five elite Australian football players from one club participated in this study. Running workloads of players were tracked using Global Positioning System technology, and were categorised using either; (1) absolute, pre-defined speed thresholds, or (2) relative, individualised speed thresholds. Players were divided into three equal groups based on maximum velocity; (1) faster, (2) moderate, or (3) slower. One-week and four-week workloads were calculated, along with the ACWR. Injuries were recorded if they were non-contact in nature and resulted in "time-loss".

RESULTS: Faster players demonstrated a significant overestimation of very high-speed running when compared to their relative thresholds (p=0.01, ES=-0.73). Similarly, slower players demonstrated an underestimation of high- (p=0.06, ES=0.55) and very high-speed (p=0.01, ES=1.16) running when compared to their relative thresholds. For slower players, (1) greater amounts of relative very high-speed running had a greater risk of injury than less (RR=8.30, p=0.04), and (2) greater absolute high-speed chronic workloads demonstrated an increase in injury likelihood (RR=2.28, p=0.16), while greater relative high-speed chronic workloads offered a decrease in injury likelihood (RR=0.33, p=0.11). Faster players with a very high-speed ACWR of >2.0 had a greater risk of injury than those between 0.49-0.99 for both absolute (RR=10.31, p=0.09) and relative (RR=4.28, p=0.13) workloads.

CONCLUSIONS: The individualisation of velocity thresholds significantly alters the amount of very high-speed running performed and should be considered in the prescription of training load.

Language: en

%G en %I Human Kinetics Publishers %@ 1555-0265 %U http://dx.doi.org/10.1123/ijspp.2017-0148